The present disclosure relates generally to the field of batteries and battery modules. More specifically, the present disclosure relates to micro-hybrid battery modules.
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
A vehicle that uses one or more battery systems for providing all or a portion of the motive power for the vehicle can be referred to as an xEV, where the term “xEV” is defined herein to include all of the following vehicles, or any variations or combinations thereof, that use electric power for all or a portion of their vehicular motive force. For example, xEVs include electric vehicles (EVs) that utilize electric power for all motive force. As will be appreciated by those skilled in the art, hybrid electric vehicles (HEVs), also considered xEVs, combine an internal combustion engine propulsion system and a battery-powered electric propulsion system, such as 48 Volt (V) or 130V systems. The term HEV may include any variation of a hybrid electric vehicle. For example, full hybrid systems (FHEVs) may provide motive and other electrical power to the vehicle using one or more electric motors, using only an internal combustion engine, or using both. In contrast, mild hybrid systems (MHEVs) disable the internal combustion engine when the vehicle is idling and utilize a battery system to continue powering the air conditioning unit, radio, or other electronics, as well as to restart the engine when propulsion is desired. The mild hybrid system may also apply some level of power assist, during acceleration for example, to supplement the internal combustion engine. Mild hybrids are typically 96V to 130V and recover braking energy through a belt or crank integrated starter generator. Further, a micro-hybrid electric vehicle (mHEV) also uses a “Start-Stop” system similar to the mild hybrids, but the micro-hybrid systems may or may not supply power assist to the internal combustion engine and operate at a voltage below 60V. In some cases, a micro-hybrid system may include two battery modules, a first battery module (e.g., 12V) and a second battery module (e.g., 48V). The second battery module (e.g., 48V) may have a high energy capacity such that it is suitable for recovering braking energy, whereas the first battery module (e.g., 12V) may have a high power capacity such that it is suitable for reigniting the engine. In addition, a plug-in electric vehicle (PEV) is any vehicle that can be charged from an external source of electricity, such as wall sockets, and the energy stored in the rechargeable battery packs drives or contributes to drive the wheels. PEVs are a subcategory of EVs that include all-electric or battery electric vehicles (BEVs), plug-in hybrid electric vehicles (PHEVs), and electric vehicle conversions of hybrid electric vehicles and conventional internal combustion engine vehicles.
xEVs as described above may provide a number of advantages as compared to more traditional gas-powered vehicles using only internal combustion engines and traditional electrical systems, which are typically 12V systems powered by a lead acid battery module. For example, xEVs may produce fewer undesirable emission products and may exhibit greater fuel efficiency as compared to traditional internal combustion vehicles and, in some cases, such xEVs may eliminate the use of gasoline entirely, as is the case of certain types of EVs or PEVs.
As technology continues to evolve, there is a need to provide improved power sources, particularly battery modules, for such vehicles and other implementations. For example, micro-hybrid battery modules may be constructed using a 12V lead acid battery and a 48V lithium ion battery. Micro-hybrid battery modules contribute a relatively large amount of weight to an xEV, which may ultimately lead to decreased fuel economy. Generally, lithium ion battery modules weigh less and have a better charge acceptance than lead acid battery modules despite being equipped with devices that control charge, control cooling, and so forth. It is now recognized that it may be desirable to simplify lithium ion battery modules, specifically those in micro-hybrid applications to improve overall vehicle performance.